Heb 7:27, Heb 9:14,25-26, Heb 10:8-12, 1 Jn 4:9-10, Mk 14:24, Mt 20:28, Rom 3:23-24, Rom 4:24-25
In the Old Testament, Isaiah prophesied that God would use Christ as a sin offering for our sins. (Isa 53:10-11)
Isa 53:10 Yet it pleased the Lord to bruise him; he hath put him to grief: when thou shalt make his soul an offering for sin, he shall see his seed, he shall prolong his days, and the pleasure of the Lord shall prosper in his hand. 11 He shall see of the travail of his soul, and shall be satisfied: by his knowledge shall my righteous servant justify many; for he shall bear their iniquities.
As the Old Testament prophesied, Jesus offered Himself as a trespass offering to God once for the forgiveness of our sins. (Hebrews 7:27, Heb 9:14,25-26, Heb 10:8-12)
Hebrews 7:27 Who needeth not daily, as those high priests, to offer up sacrifice, first for his own sins, and then for the people's: for this he did once, when he offered up himself.
Heb 9:14 How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God? 25 Nor yet that he should offer himself often, as the high priest entereth into the holy place every year with blood of others; 26 For then must he often have suffered since the foundation of the world: but now once in the end of the world hath he appeared to put away sin by the sacrifice of himself.
Heb 10:8 Above when he said, Sacrifice and offering and burnt offerings and offering for sin thou wouldest not, neither hadst pleasure therein; which are offered by the law; 9 Then said he, Lo, I come to do thy will, O God. He taketh away the first, that he may establish the second. 10 By the which will we are sanctified through the offering of the body of Jesus Christ once for all. 11 And every priest standeth daily ministering and offering oftentimes the same sacrifices, which can never take away sins: 12 But this man, after he had offered one sacrifice for sins for ever, sat down on the right hand of God;
God loves us so much that He sent His only begotten Son into this world as a propitiation sacrifice. (1 John 4:9-10)
1 John 4:9 In this was manifested the love of God toward us, because that God sent his only begotten Son into the world, that we might live through him. 10 Herein is love, not that we loved God, but that he loved us, and sent his Son to be the propitiation for our sins.
Jesus willingly shed His blood to save us. (Mark 14:24, Matthew 20:28)
Mark 14:24 And he said unto them, This is my blood of the new testament, which is shed for many.
Matthew 20:28 Even as the Son of man came not to be ministered unto, but to minister, and to give his life a ransom for many.
We are justified because Jesus died for us and rose again. (Romans 3:23-24, Romans 4:24-25)
Romans 3:23 For all have sinned, and come short of the glory of God; 24 Being justified freely by his grace through the redemption that is in Christ Jesus:
Romans 4:24 But for us also, to whom it shall be imputed, if we believe on him that raised up Jesus our Lord from the dead; 25 Who was delivered for our offences, and was raised again for our justification.